Evaluation of physical dysfunction in cats with naturally occurring osteoarthritis

Osteoarthritis (OA) is a common cause of chronic pain and physical dysfunction in cats. Clinical signs are often subtle and lameness is rarely the chief complaint. The main clinical features consist of gradual changes in the cat’s behaviour and everyday living. The changes are often misinterpreted as part of normal ageing. In a clinical setting, the diagnosis is based on information from the owner, physical examination and radiography. However, conflicting physical and radiographic signs makes feline OA challenging to diagnose. Improved tools are needed as diagnostic aid and to evaluate treatment efficacy. The overall aim of the thesis was to improve methods for diagnosis and evaluation of treatment in cats with naturally occurring OA. Since chronic pain can only be measured indirectly, physical dysfunction caused by OA was measured. The alteration in physical dysfunction was evaluated using physical examination, objective pressure mat technique and subjective owner assessment questionnaires. The specific aims were to: establish reference values from gait analysis in sound cats, compare kinetic data from sound cats walking on the pressure mat with results from OA cats, evaluate four different questionnaires regarding validity and reliability, and in a clinical pilot study evaluate the effects of pain relieving treatment in OA cats using the pressure mat and the questionnaires. The acquired reference values from sound cats confirmed that cats have a similar gait symmetry and front-hind asymmetry as dogs. Peak vertical force and vertical impulse were reliable gait parameters to analyse. Cats with OA and cranial cruciate ligament injury were compared to sound control cats. The cats with OA put load on their paws more unevenly and had a different behaviour in the home environment, compared to sound cats. The four questionnaires that were evaluated all had sound validity and reliability. The clinical pilot study comparing meloxicam and robenacoxib, showed that osteoarthritic cats that received pain-relieving drugs improved significantly. The thesis contributes to evaluation of physical dysfunction in osteoarthritic cats by using objective pressure mat technique and subjective questionnaires. This leads to improved management of chronic pain in cats with OA and improved feline welfare